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• 1. [Article] The effects on salmon populations of the partial elimination of fixed fishing gear on the Columbia River in 1935

  1. Six major types of commercial gear have been used to take salmon and steelhead on the Columbia River; namely, gill nets, set nets, seines, traps, fish wheels and dip nets. 2. The five important commercial ...

  Citation × Citation Citation Abstract Copy Title: The effects on salmon populations of the partial elimination of fixed fishing gear on the Columbia River in 1935 Author: Johnson, Donald R., Chapman, Wilbert McLeod, 1910-1970, Oregon. Fish Commission, Schoning, Robert W. 1. Six major types of commercial gear have been used to take salmon and steelhead on the Columbia River; namely, gill nets, set nets, seines, traps, fish wheels and dip nets. 2. The five important commercial species in the Columbia River are chinook, silver, blueback and chum salmon and steelhead trout. 3. In 1927 fish wheels were eliminated in Oregon. In 1935 fish wheels, traps, seines and set nets were eliminated in Washington. 4. The effect of the gear change in Washington in 1935 has been to increase the take in other gears, while the previous trend of total landings has not changed appreciably. 5. There is no conclusive evidence that the elimination of fixed gear in Washington increased the escapement of salmon and steelhead. 6. There is no conclusive evidence that any gear is injurious to the run except by subtracting fish from the run. 7. Measures designed to increase the escapement should apply to all gears and cover the entire life history of each species. Title: The effects on salmon populations of the partial elimination of fixed fishing gear on the Columbia River in 1935 Author: Johnson, Donald R., Chapman, Wilbert McLeod, 1910-1970, Oregon. Fish Commission, Schoning, Robert W. 1. Six major types of commercial gear have been used to take salmon and steelhead on the Columbia River; namely, gill nets, set nets, seines, traps, fish wheels and dip nets. 2. The five important commercial species in the Columbia River are chinook, silver, blueback and chum salmon and steelhead trout. 3. In 1927 fish wheels were eliminated in Oregon. In 1935 fish wheels, traps, seines and set nets were eliminated in Washington. 4. The effect of the gear change in Washington in 1935 has been to increase the take in other gears, while the previous trend of total landings has not changed appreciably. 5. There is no conclusive evidence that the elimination of fixed gear in Washington increased the escapement of salmon and steelhead. 6. There is no conclusive evidence that any gear is injurious to the run except by subtracting fish from the run. 7. Measures designed to increase the escapement should apply to all gears and cover the entire life history of each species. Close

• 2. [Article] Tuberculosis in Pacific salmon and steelhead trout

  Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies ...

  Citation × Citation Citation Abstract Copy Title: Tuberculosis in Pacific salmon and steelhead trout Author: Ordal, Erling Josef, 1906-, Oregon. Fish Commission, Wood, James W. Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies reported here, tuberculosis was found not only in adult spring chinook but in silver salmon (0. kisutch), blueback salmon (0. nerka), and in anadromous and resident strains of rainbow trout (Salmo gairdnerii). Advanced tuberculosis was found in salmonoid fishes held in fresh water for two years or longer, as well as in adults returning from the sea. Lesions were most frequently observed in the liver, and varied in size from small miliary tubercles to huge necrotic areas, filled with characteristic acid-fast bacilli. The typical bacilli were found in stained smears from the kidney, heart, musculature, brain, intestines, pyloric caeca, and roe of infected fish. The disease was originally observed in sexually-underdeveloped fish, and there is indication that it interferes with sexual maturation. It was found that tuberculosis in marked salmon known to be of hatchery origin was extremely high - in some cases 100 percent. Tuberculosis was absent in the small number of silver and chum salmon examined which were known to be the progeny from natural spawning. It is suggested that dissemination of the disease may be due to fish-cultural practices such as the feeding of untreated carcasses and the viscera from tuberculous fish. Since acid-fast bacilli were found in the roe of some fish, it is also suggested that the disease may be transmitted to healthy eggs during the process of fertilization. Tuberculous adult spring chinook were found less capable of surviving to maturity after they reached the spawning grounds than were non-infected fish. It is likely that tuberculosis also influences the ability of salmon to survive during earlier stages of their life history. The incidence of tuberculosis in adult spring chinook entering the Dexter holding ponds on the Middle Fork of the Willamette River in 1955 and 1956 was 8.7 and 6.1 percent, respectively. The increase in incidence to 58.8 percent in 1957 is attributed to the increased dependency of the run on artificial propagation necessitated by the construction of Lookout Point Dam. Among chinook caught in the Columbia River gill-net fishery in. February and in May 1956, 12.3 and 10.5 percent, respectively, of those examined were tuberculous. Although these are spring chinook, it is believed that hatchery reared fall chinook also entered the catch, especially during May, and may have contributed to the number of tuberculous fish taken. Title: Tuberculosis in Pacific salmon and steelhead trout Author: Ordal, Erling Josef, 1906-, Oregon. Fish Commission, Wood, James W. Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies reported here, tuberculosis was found not only in adult spring chinook but in silver salmon (0. kisutch), blueback salmon (0. nerka), and in anadromous and resident strains of rainbow trout (Salmo gairdnerii). Advanced tuberculosis was found in salmonoid fishes held in fresh water for two years or longer, as well as in adults returning from the sea. Lesions were most frequently observed in the liver, and varied in size from small miliary tubercles to huge necrotic areas, filled with characteristic acid-fast bacilli. The typical bacilli were found in stained smears from the kidney, heart, musculature, brain, intestines, pyloric caeca, and roe of infected fish. The disease was originally observed in sexually-underdeveloped fish, and there is indication that it interferes with sexual maturation. It was found that tuberculosis in marked salmon known to be of hatchery origin was extremely high - in some cases 100 percent. Tuberculosis was absent in the small number of silver and chum salmon examined which were known to be the progeny from natural spawning. It is suggested that dissemination of the disease may be due to fish-cultural practices such as the feeding of untreated carcasses and the viscera from tuberculous fish. Since acid-fast bacilli were found in the roe of some fish, it is also suggested that the disease may be transmitted to healthy eggs during the process of fertilization. Tuberculous adult spring chinook were found less capable of surviving to maturity after they reached the spawning grounds than were non-infected fish. It is likely that tuberculosis also influences the ability of salmon to survive during earlier stages of their life history. The incidence of tuberculosis in adult spring chinook entering the Dexter holding ponds on the Middle Fork of the Willamette River in 1955 and 1956 was 8.7 and 6.1 percent, respectively. The increase in incidence to 58.8 percent in 1957 is attributed to the increased dependency of the run on artificial propagation necessitated by the construction of Lookout Point Dam. Among chinook caught in the Columbia River gill-net fishery in. February and in May 1956, 12.3 and 10.5 percent, respectively, of those examined were tuberculous. Although these are spring chinook, it is believed that hatchery reared fall chinook also entered the catch, especially during May, and may have contributed to the number of tuberculous fish taken. Close